(or NULL to get "Nautilus: Error" and the like). Updated
	all callers to pass a window title.

	* libnautilus-extensions/nautilus-stock-dialogs.h,
	* libnautilus-extensions/nautilus-stock-dialogs.c:
	(show_message_box), (show_ok_box), (nautilus_info_dialog),
	(nautilus_warning_dialog), (nautilus_error_dialog),
	(nautilus_error_dialog_with_details), (nautilus_yes_no_dialog):
	Updated all public & private dialog-creating calls to take
	a dialog_title parameter.

	* components/rpmview/nautilus-rpm-view-install.c:
	(nautilus_rpm_view_install_done):
	* libnautilus-extensions/nautilus-file-operations.c:
	(confirm_empty_trash):
	* libnautilus-extensions/nautilus-program-chooser.c:
	(nautilus_program_chooser_show_no_choices_message):
	* libnautilus-extensions/nautilus-program-choosing.c:
	(nautilus_launch_application_parented):
	* src/file-manager/fm-error-reporting.c:
	(fm_report_error_renaming_file), (fm_report_error_setting_group),
	(fm_report_error_setting_owner),
	(fm_report_error_setting_permissions):
	* src/nautilus-application.c:
	(nautilus_application_check_user_directories),
	(nautilus_application_startup):
	* src/nautilus-first-time-druid.c:
	(nautilus_first_time_druid_show):
	* src/nautilus-property-browser.c: (emblem_image_file_changed),
	(add_background_to_browser):
	* src/nautilus-sidebar.c: (receive_dropped_uri_list):
	* src/nautilus-window-manage-views.c: (handle_unreadable_location),
	(report_content_view_failure_to_user),
	(report_sidebar_panel_failure_to_user),
	(nautilus_window_end_location_change_callback):
	* src/nautilus-window-menus.c: (forget_history_if_confirmed),
	(show_bogus_bookmark_window): Made up dialog titles for all
	title-less dialogs. A few were already setting titles after
	the fact, so I removed the now-extraneous set_title calls.